Furnace



Nov. 24, 1931. J. w. C.HRISTIE 1,833,047

' FURNACE Filed May .51, 1929 2 Sheets-Sheet 1 In verz for: J M. C'hr-(s fie.

Nov. 24, 1931. J. w. CHRISTIE 1,833,047

' FURNACE Filed May 31, 1929 2 Sheets-Slieet 2 a// /////E W .mM 6% n t n e w w w m H. a? w vi lll l Patented Nov. 2 4, 1931 UNITED STATES JAIIEs w. crims'rm' or mmnmronls, mlnnnsora summon 3 a ncauonnlea Kay 31.1929. Serial No. 367,202.

My invention relates to furnaces, and more particularly to furnaces intended for burning fine coal. An object of the invention is to provide means for causing the fire to burn up quickly in the morning when the furnace is charged with fresh fuel, and for securing more perfect co'mbustionof fuel than is attained with furnaces now in common use; In the use of furnaces which are extensively employed, the fire is slow in'starting up in the morning after being banked for the night. and furthermore only an imp'erfectcombustion of the fuel is obtained so that a considerable percentage of the gaseous products-passes out into the air in an unconsumed condition. The result of this is that a largeamount of heat is wasted and quantities of smoke and soot are discharged into the atmosphere with resultant injurious effects;* In carrying out plate which is placed in the firebox in spaced relation above the grate and-in spaced relation ahead of the-rearportion of the shell of the furnace so that the gasesfrom the coal I: pass through" the perforations of the bafiie plate into a space at the rear thereofwhich is just above a hot spot produced. by live coal which does not become covered with fresh In the accompanying drawings which illustrate a practicalembodiment of my inven tion, Fig. 1 is a View in'central vertical section showing my improved feature in combination with a furnace. Fig. 2 is a view in iorizontal section on the line 2 2 ofFig. 1. Fig. 3 is a View on an enlarged scale and in vertical section through the furnace wall taken at riglit'angles to Fig. 1.. Fig. 4 is a View in horizontal section on the line 4-4 of Fig. 3. Fig. 5 is a perspective view of a modified construction.

My device is adapted to be used in connection with furnaces of well known construction and as shown in the drawings, the furnace includes a shell having inner and outer .margin which myinvention, I provide a perforated baflie' walls 10 and 12 spaced from each other. This shell is provided with the customary charging door toward the upper portion thereof below which there isa firebox l5 and a grate 16 at the bottom underneath which '55 '1 there is an ashpit 18. At the upper portion of the shell, cutomary water chambers 20 and a smoke pipe 22v are provided. The outlet from the firebox isout of vertical alinement with the pipe or flue 22 of the furnace. As best shown in Fig. l, a baflie plate 24 is. placed in the furnace in such position as to be spaced from the rear of the shell and above the grate. As shown in Figs. 1 to 4, the baffle plate is constructed of metal and has a Water passage 26 around inside of its thickened prevents the plate from being burned out. Water inlet and outlet pipes 28 and 30 are connected with the water passage 26, these pipes extending out through the shell of the furnace and serving to support the bafiie plate in proper position. Inside of its margin, the bafiie plate consists of a thinner member 32 which is provided with a multiplicity of perforations 34 and two diagonal slots 56, these slots serving to take care of expansion and contraction. in the form shown in Fig. 5, I provide a baflie plate 38 which is made of fire-clay without any water passage and is supported Within the shell of the furnace in any suitable manner. .The central portion of this plate is made thinner than the margin and is provided with a mulv tiplicity of perforations 40.

The operation and advantages of my in vention will be understood in connection with the foregoing description. WVhenthe furnace has just been charged with fuel, the condition thereof is indicated in Fig. 1 in which there is a bed of live coal 42 above the ashes 44, and a charge of fresh fuel 46 above the live coal and piled up in front of the baflle plate. Air entering. the ashpit takes the path of least resistance indicated by the arrows 48 and flows up through the live coal into the space back of thebaflie plate. Air entering through openings in the charging door takes Y the path designated by the arrows 50 and 5 since thisair is cold, it follows the contour of the upper surface of the-.coalto the rear of;

the balile plate. Gases from the live coal follow the path indicated by the arrows 51 and pass through the perforations 84 in the baflle plate to the space at the rear thereof. During the night, the coal burns down to about the position indicated by the dotted line 52. Before the furnace is charged, some of the live coal is pushed back under the baffie plate so as to produce a hot spot as indicated at 54 located at the bottom of the space at the rear of the baffle plate. This hot spot causes the gases coming from the fresh coal to be ignited in the space at the rear of the baflle plate instead of passing up in non-ignite-d condition to the smoke pipe. Furthermore, the provision of the baffle plate reduces the percentage of gaseous products passing from the furnace in unconsumed condition during the continued operation of the furnace. The ballle plate shown in Fig. 5 being made of fire-clay or other similar highly fire-resistant material, does not need any water passage therein for its protection. In the form shown in Figs. 1 to 1, the bathe plate is protected and prevented from being burned out on account of the provision of the water passage which incidentally maybe used to supply hot water.

The operation and advantages of my invention may be summarized as follows:

1. It provides a construction whereby all the gases are burned as they accumulate.

2.'It permits the burning of the smaller sizes of anthracite coal such as nut and pea mixed, pea, buckwheat or rice, without fear of explosion even though the coal should contain a considerable amount of screenings.

3. It permits the burning of egg or stove size anthracite, coke or any of the many kinds of soft coals with a heavy banking of buckwheat.

.4. It acts as a self feeder until the flow of coal stops, as shown by the dotted line from the feed door to below the baffle plate in Fig. 1. a

5. It provides at all times a hot spot directly back of the baffle plate at the junction of the lower part of fiow at the extreme bottom point which can be depended upon to ignite all gases as they accumulate.

.6. It .does not require a blower of any kind thereby avoiding the formation of clinkers.

7. It permits the carrying of a very low fire in mild weather while rapidly bringing it up if the weather changes to colder.

8. It permits the induction over and through the fire of all of the oxygen that the gases will take without cooling the fire, thereby getting considerably more value out of the coal burned than with ordinary. methods.-

9. It allows for an extremely long burning gas travel as indicated by the arrows in Fig. 1.

10. The air overthe top of the coal drives the gases back and through the b'aflle plate the chimney as generally happens.

12. It allows the twist damper to be nearly closed, thereby retaining the heat from the burning gases in the combustion chamber and in between the plates as shown in Fig. l.

13. It permits the firing of enough coal at one time in extreme cold weather to carry the fire from twelve to fifteen hours. During mild weather in spring and fall, the same firing of coal will carry from forty-eight hours to sixty hours. This pertains particularly to buckwheat size or smaller.

14. The baflie plate may be readily made of cast iron and when water-cooled, it will not burn out. I

15. It can be connected directly to the water supply in hot water plants, thereby giving the plant more heating surface.

I claim:

1. A furnace comprising a shell enclosing a firebox having an outlet passage only at the upper and forward portion thereof, a grate at the bottom thereof, and a perforated bafile plate positioned in spaced relation above said grate and in spaced relation forward of the rear portion of said shell.

2. A furnace comprising a shell enclosing a firebox, having an outlet passage only at the upper and forward portion thereof, a grate at the bottom thereof, a charging door at the upper front portion ofsaid shell, and a perforated baflle plate positioned at a lower level than said charging door in spaced relation above said grate and in spaced relation forward of the rear portion of said shell.

3. A furnace comprising a shell enclosing a firebox having an outlet passage only at the upper and forward portion thereof, a grate at the bottom of said firebox, a charging door at the upper front portion of said shell, and a vertically extending bafiie plate provided with a multiplicity of horizontally extending perforations and positioned at a lower level than saidcharging door in spaced relation above said grate and in spaced relation forward of the rear portion of said shell.

Intestimony whereof I hereunto affix my signature.

JAMES W. CHRISTIE. 

